The area of a rectangle is 660 cm2 and the length of its diagonal is 61 cm.…
2022
The area of a rectangle is 660 cm2 and the length of its diagonal is 61 cm. What is the perimeter (in cm) of the rectangle?
Answer: D. 142 — Let length and breadth be l and b. Given lb = 660 and l² + b² = 61² = 3721. Now (l + b)² = l² + b² + 2lb = 3721 + 1320 = 5041 = 71². Thus l + b = 71 and…
- A.
136
- B.
138
- C.
140
- D.
142
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Correct answer: D
Let length and breadth be l and b. Given lb = 660 and l² + b² = 61² = 3721. Now (l + b)² = l² + b² + 2lb = 3721 + 1320 = 5041 = 71². Thus l + b = 71 and perimeter = 2(l + b) = 142 cm.
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